The patch titled
Subject: mm: correct the docs for thp_fault_alloc and thp_fault_fallback
has been added to the -mm mm-unstable branch. Its filename is
mm-correct-the-docs-for-thp_fault_alloc-and-thp_fault_fallback.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-correct-the-docs-for-thp_fault_alloc-and-thp_fault_fallback.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Barry Song <v-songbaohua@xxxxxxxx>
Subject: mm: correct the docs for thp_fault_alloc and thp_fault_fallback
Date: Fri, 12 Apr 2024 23:48:58 +1200
The documentation does not align with the code. In
__do_huge_pmd_anonymous_page(), THP_FAULT_FALLBACK is incremented when
mem_cgroup_charge() fails, despite the allocation succeeding, whereas
THP_FAULT_ALLOC is only incremented after a successful charge.
Link: https://lkml.kernel.org/r/20240412114858.407208-5-21cnbao@xxxxxxxxx
Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx>
Reviewed-by: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Chris Li <chrisl@xxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Domenico Cerasuolo <cerasuolodomenico@xxxxxxxxx>
Cc: Kairui Song <kasong@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Cc: Yu Zhao <yuzhao@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/mm/transhuge.rst | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/Documentation/admin-guide/mm/transhuge.rst~mm-correct-the-docs-for-thp_fault_alloc-and-thp_fault_fallback
+++ a/Documentation/admin-guide/mm/transhuge.rst
@@ -369,7 +369,7 @@ monitor how successfully the system is p
thp_fault_alloc
is incremented every time a huge page is successfully
- allocated to handle a page fault.
+ allocated and charged to handle a page fault.
thp_collapse_alloc
is incremented by khugepaged when it has found
@@ -377,7 +377,7 @@ thp_collapse_alloc
successfully allocated a new huge page to store the data.
thp_fault_fallback
- is incremented if a page fault fails to allocate
+ is incremented if a page fault fails to allocate or charge
a huge page and instead falls back to using small pages.
thp_fault_fallback_charge
_
Patches currently in -mm which might be from v-songbaohua@xxxxxxxx are
arm64-mm-swap-support-thp_swap-on-hardware-with-mte.patch
mm-hold-ptl-from-the-first-pte-while-reclaiming-a-large-folio.patch
mm-alloc_anon_folio-avoid-doing-vma_thp_gfp_mask-in-fallback-cases.patch
mm-add-per-order-mthp-anon_fault_alloc-and-anon_fault_fallback-counters.patch
mm-add-per-order-mthp-anon_swpout-and-anon_swpout_fallback-counters.patch
mm-add-docs-for-per-order-mthp-counters-and-transhuge_page-abi.patch
mm-correct-the-docs-for-thp_fault_alloc-and-thp_fault_fallback.patch
